X-Git-Url: http://git.meshlink.io/?a=blobdiff_plain;f=src%2Futcp.c;fp=src%2Futcp.c;h=0909a0101e196fdecc91b991948c4e5495b10380;hb=2178842d04c649ed22457dc0829153fd1092521c;hp=dc30fe69c603278549694cc8b6c24225ee28956e;hpb=0e03a8ad0de862ea431110d27d4659c082855f98;p=meshlink-tiny

diff --git a/src/utcp.c b/src/utcp.c
index dc30fe6..0909a01 100644
--- a/src/utcp.c
+++ b/src/utcp.c
@@ -186,274 +186,6 @@ static int32_t seqdiff(uint32_t a, uint32_t b) {
 	return a - b;
 }
 
-// Buffer functions
-static bool buffer_wraps(struct buffer *buf) {
-	return buf->size - buf->offset < buf->used;
-}
-
-static bool buffer_resize(struct buffer *buf, uint32_t newsize) {
-	assert(!buf->external);
-
-	if(!newsize) {
-		free(buf->data);
-		buf->data = NULL;
-		buf->size = 0;
-		buf->offset = 0;
-		return true;
-	}
-
-	char *newdata = realloc(buf->data, newsize);
-
-	if(!newdata) {
-		return false;
-	}
-
-	buf->data = newdata;
-
-	if(buffer_wraps(buf)) {
-		// Shift the right part of the buffer until it hits the end of the new buffer.
-		// Old situation:
-		// [345......012]
-		// New situation:
-		// [345.........|........012]
-		uint32_t tailsize = buf->size - buf->offset;
-		uint32_t newoffset = newsize - tailsize;
-		memmove(buf->data + newoffset, buf->data + buf->offset, tailsize);
-		buf->offset = newoffset;
-	}
-
-	buf->size = newsize;
-	return true;
-}
-
-// Store data into the buffer
-static ssize_t buffer_put_at(struct buffer *buf, size_t offset, const void *data, size_t len) {
-	debug(NULL, "buffer_put_at %lu %lu %lu\n", (unsigned long)buf->used, (unsigned long)offset, (unsigned long)len);
-
-	// Ensure we don't store more than maxsize bytes in total
-	size_t required = offset + len;
-
-	if(required > buf->maxsize) {
-		if(offset >= buf->maxsize) {
-			return 0;
-		}
-
-		len = buf->maxsize - offset;
-		required = buf->maxsize;
-	}
-
-	// Check if we need to resize the buffer
-	if(required > buf->size) {
-		size_t newsize = buf->size;
-
-		if(!newsize) {
-			newsize = 4096;
-		}
-
-		do {
-			newsize *= 2;
-		} while(newsize < required);
-
-		if(newsize > buf->maxsize) {
-			newsize = buf->maxsize;
-		}
-
-		if(!buffer_resize(buf, newsize)) {
-			return -1;
-		}
-	}
-
-	uint32_t realoffset = buf->offset + offset;
-
-	if(buf->size - buf->offset <= offset) {
-		// The offset wrapped
-		realoffset -= buf->size;
-	}
-
-	if(buf->size - realoffset < len) {
-		// The new chunk of data must be wrapped
-		memcpy(buf->data + realoffset, data, buf->size - realoffset);
-		memcpy(buf->data, (char *)data + buf->size - realoffset, len - (buf->size - realoffset));
-	} else {
-		memcpy(buf->data + realoffset, data, len);
-	}
-
-	if(required > buf->used) {
-		buf->used = required;
-	}
-
-	return len;
-}
-
-static ssize_t buffer_put(struct buffer *buf, const void *data, size_t len) {
-	return buffer_put_at(buf, buf->used, data, len);
-}
-
-// Copy data from the buffer without removing it.
-static ssize_t buffer_copy(struct buffer *buf, void *data, size_t offset, size_t len) {
-	// Ensure we don't copy more than is actually stored in the buffer
-	if(offset >= buf->used) {
-		return 0;
-	}
-
-	if(buf->used - offset < len) {
-		len = buf->used - offset;
-	}
-
-	uint32_t realoffset = buf->offset + offset;
-
-	if(buf->size - buf->offset <= offset) {
-		// The offset wrapped
-		realoffset -= buf->size;
-	}
-
-	if(buf->size - realoffset < len) {
-		// The data is wrapped
-		memcpy(data, buf->data + realoffset, buf->size - realoffset);
-		memcpy((char *)data + buf->size - realoffset, buf->data, len - (buf->size - realoffset));
-	} else {
-		memcpy(data, buf->data + realoffset, len);
-	}
-
-	return len;
-}
-
-// Discard data from the buffer.
-static ssize_t buffer_discard(struct buffer *buf, size_t len) {
-	if(buf->used < len) {
-		len = buf->used;
-	}
-
-	if(buf->size - buf->offset <= len) {
-		buf->offset -= buf->size;
-	}
-
-	if(buf->used == len) {
-		buf->offset = 0;
-	} else {
-		buf->offset += len;
-	}
-
-	buf->used -= len;
-
-	return len;
-}
-
-static void buffer_clear(struct buffer *buf) {
-	buf->used = 0;
-	buf->offset = 0;
-}
-
-static bool buffer_set_size(struct buffer *buf, uint32_t minsize, uint32_t maxsize) {
-	if(maxsize < minsize) {
-		maxsize = minsize;
-	}
-
-	buf->maxsize = maxsize;
-
-	return buf->size >= minsize || buffer_resize(buf, minsize);
-}
-
-static void buffer_transfer(struct buffer *buf, char *newdata, size_t newsize) {
-	if(buffer_wraps(buf)) {
-		// Old situation:
-		// [345......012]
-		// New situation:
-		// [012345......]
-		uint32_t tailsize = buf->size - buf->offset;
-		memcpy(newdata, buf->data + buf->offset, tailsize);
-		memcpy(newdata + tailsize, buf->data, buf->used - tailsize);
-	} else {
-		// Old situation:
-		// [....012345..]
-		// New situation:
-		// [012345......]
-		memcpy(newdata, buf->data + buf->offset, buf->used);
-	}
-
-	buf->offset = 0;
-	buf->size = newsize;
-}
-
-static void set_buffer_storage(struct buffer *buf, char *data, size_t size) {
-	if(size > UINT32_MAX) {
-		size = UINT32_MAX;
-	}
-
-	buf->maxsize = size;
-
-	if(data) {
-		if(buf->external) {
-			// Don't allow resizing an external buffer
-			abort();
-		}
-
-		if(size < buf->used) {
-			// Ignore requests for an external buffer if we are already using more than it can store
-			return;
-		}
-
-		// Transition from internal to external buffer
-		buffer_transfer(buf, data, size);
-		free(buf->data);
-		buf->data = data;
-		buf->external = true;
-	} else if(buf->external) {
-		// Transition from external to internal buf
-		size_t minsize = buf->used <= DEFAULT_SNDBUFSIZE ? DEFAULT_SNDBUFSIZE : buf->used;
-
-		if(minsize) {
-			data = malloc(minsize);
-
-			if(!data) {
-				// Cannot handle this
-				abort();
-			}
-
-			buffer_transfer(buf, data, minsize);
-			buf->data = data;
-		} else {
-			buf->data = NULL;
-			buf->size = 0;
-		}
-
-		buf->external = false;
-	} else {
-		// Don't do anything if the buffer wraps
-		if(buffer_wraps(buf)) {
-			return;
-		}
-
-		// Realloc internal storage
-		size_t minsize = max(DEFAULT_SNDBUFSIZE, buf->offset + buf->used);
-
-		if(minsize) {
-			data = realloc(buf->data, minsize);
-
-			if(data) {
-				buf->data = data;
-				buf->size = minsize;
-			}
-		} else {
-			free(buf->data);
-			buf->data = NULL;
-			buf->size = 0;
-		}
-	}
-}
-
-static void buffer_exit(struct buffer *buf) {
-	if(!buf->external) {
-		free(buf->data);
-	}
-
-	memset(buf, 0, sizeof(*buf));
-}
-
-static uint32_t buffer_free(const struct buffer *buf) {
-	return buf->maxsize > buf->used ? buf->maxsize - buf->used : 0;
-}
-
 // Connections are stored in a sorted list.
 // This gives O(log(N)) lookup time, O(N log(N)) insertion time and O(N) deletion time.
 
@@ -498,8 +230,6 @@ static void free_connection(struct utcp_connection *c) {
 	memmove(cp, cp + 1, (utcp->nconnections - i - 1) * sizeof(*cp));
 	utcp->nconnections--;
 
-	buffer_exit(&c->rcvbuf);
-	buffer_exit(&c->sndbuf);
 	free(c);
 }
 
@@ -548,17 +278,6 @@ static struct utcp_connection *allocate_connection(struct utcp *utcp, uint16_t s
 		return NULL;
 	}
 
-	if(!buffer_set_size(&c->sndbuf, DEFAULT_SNDBUFSIZE, DEFAULT_MAXSNDBUFSIZE)) {
-		free(c);
-		return NULL;
-	}
-
-	if(!buffer_set_size(&c->rcvbuf, DEFAULT_RCVBUFSIZE, DEFAULT_MAXRCVBUFSIZE)) {
-		buffer_exit(&c->sndbuf);
-		free(c);
-		return NULL;
-	}
-
 	// Fill in the details
 
 	c->src = src;
@@ -666,7 +385,7 @@ struct utcp_connection *utcp_connect_ex(struct utcp *utcp, uint16_t dst, utcp_re
 	pkt.hdr.dst = c->dst;
 	pkt.hdr.seq = c->snd.iss;
 	pkt.hdr.ack = 0;
-	pkt.hdr.wnd = c->rcvbuf.maxsize;
+	pkt.hdr.wnd = c->utcp->mtu;
 	pkt.hdr.ctl = SYN;
 	pkt.hdr.aux = 0x0101;
 	pkt.init[0] = 1;
@@ -699,28 +418,7 @@ void utcp_accept(struct utcp_connection *c, utcp_recv_t recv, void *priv) {
 	set_state(c, ESTABLISHED);
 }
 
-static void ack(struct utcp_connection *c, bool sendatleastone) {
-	int32_t left = seqdiff(c->snd.last, c->snd.nxt);
-	int32_t cwndleft = MAX_UNRELIABLE_SIZE;
-
-	assert(left >= 0);
-
-	if(cwndleft <= 0) {
-		left = 0;
-	} else if(cwndleft < left) {
-		left = cwndleft;
-
-		if(!sendatleastone || cwndleft > c->utcp->mss) {
-			left -= left % c->utcp->mss;
-		}
-	}
-
-	debug(c, "cwndleft %d left %d\n", cwndleft, left);
-
-	if(!left && !sendatleastone) {
-		return;
-	}
-
+static void ack(struct utcp_connection *c, const void *data, size_t len) {
 	struct {
 		struct hdr hdr;
 		uint8_t data[];
@@ -733,34 +431,31 @@ static void ack(struct utcp_connection *c, bool sendatleastone) {
 	pkt->hdr.ctl = ACK;
 	pkt->hdr.aux = 0;
 
-	do {
-		uint32_t seglen = left > c->utcp->mss ? c->utcp->mss : left;
-		pkt->hdr.seq = c->snd.nxt;
-
-		buffer_copy(&c->sndbuf, pkt->data, seqdiff(c->snd.nxt, c->snd.una), seglen);
+	uint32_t seglen = len;
+	pkt->hdr.seq = c->snd.nxt;
 
-		c->snd.nxt += seglen;
-		left -= seglen;
+	c->snd.nxt += seglen;
 
-		if(seglen && fin_wanted(c, c->snd.nxt)) {
-			seglen--;
-			pkt->hdr.ctl |= FIN;
-		}
+	if(fin_wanted(c, c->snd.nxt)) {
+		pkt->hdr.ctl |= FIN;
+	}
 
-		if(!c->rtt_start.tv_sec) {
-			// Start RTT measurement
-			clock_gettime(UTCP_CLOCK, &c->rtt_start);
-			c->rtt_seq = pkt->hdr.seq + seglen;
-			debug(c, "starting RTT measurement, expecting ack %u\n", c->rtt_seq);
-		}
+	if(data && len) {
+		assert(len <= c->utcp->mtu);
+		memcpy(pkt->data, data, len);
+	} else {
+		assert(!data && !len);
+	}
 
-		print_packet(c, "send", pkt, sizeof(pkt->hdr) + seglen);
-		c->utcp->send(c->utcp, pkt, sizeof(pkt->hdr) + seglen);
+	if(!c->rtt_start.tv_sec) {
+		// Start RTT measurement
+		clock_gettime(UTCP_CLOCK, &c->rtt_start);
+		c->rtt_seq = pkt->hdr.seq + seglen;
+		debug(c, "starting RTT measurement, expecting ack %u\n", c->rtt_seq);
+	}
 
-		if(left) {
-			pkt->hdr.wnd += seglen;
-		}
-	} while(left);
+	print_packet(c, "send", pkt, sizeof(pkt->hdr) + seglen);
+	c->utcp->send(c->utcp, pkt, sizeof(pkt->hdr) + seglen);
 }
 
 ssize_t utcp_send(struct utcp_connection *c, const void *data, size_t len) {
@@ -804,15 +499,9 @@ ssize_t utcp_send(struct utcp_connection *c, const void *data, size_t len) {
 		return -1;
 	}
 
-	// Add data to send buffer.
-
-	if(c->state != SYN_SENT && c->state != SYN_RECEIVED) {
-		if(len > MAX_UNRELIABLE_SIZE || buffer_put(&c->sndbuf, data, len) != (ssize_t)len) {
-			errno = EMSGSIZE;
-			return -1;
-		}
-	} else {
-		return 0;
+	if(len > MAX_UNRELIABLE_SIZE || len > c->utcp->mtu) {
+		errno = EMSGSIZE;
+		return -1;
 	}
 
 	if(len <= 0) {
@@ -827,10 +516,9 @@ ssize_t utcp_send(struct utcp_connection *c, const void *data, size_t len) {
 		return len;
 	}
 
-	ack(c, false);
+	ack(c, data, len);
 
 	c->snd.una = c->snd.nxt = c->snd.last;
-	buffer_discard(&c->sndbuf, c->sndbuf.used);
 
 	return len;
 }
@@ -857,7 +545,7 @@ static void retransmit(struct utcp_connection *c) {
 
 	pkt->hdr.src = c->src;
 	pkt->hdr.dst = c->dst;
-	pkt->hdr.wnd = c->rcvbuf.maxsize;
+	pkt->hdr.wnd = c->utcp->mtu;
 	pkt->hdr.aux = 0;
 
 	switch(c->state) {
@@ -1048,8 +736,6 @@ ssize_t utcp_recv(struct utcp *utcp, const void *data, size_t len) {
 		ptr += 2;
 	}
 
-	bool has_data = len || (hdr.ctl & (SYN | FIN));
-
 	// Is it for a new connection?
 
 	if(!c) {
@@ -1104,7 +790,7 @@ synack:
 			pkt.hdr.dst = c->dst;
 			pkt.hdr.ack = c->rcv.irs + 1;
 			pkt.hdr.seq = c->snd.iss;
-			pkt.hdr.wnd = c->rcvbuf.maxsize;
+			pkt.hdr.wnd = c->utcp->mtu;
 			pkt.hdr.ctl = SYN | ACK;
 
 			if(init) {
@@ -1224,8 +910,6 @@ synack:
 			// The peer has aborted our connection.
 			set_state(c, CLOSED);
 			errno = ECONNRESET;
-			buffer_clear(&c->sndbuf);
-			buffer_clear(&c->rcvbuf);
 
 			if(c->recv) {
 				c->recv(c, NULL, 0);
@@ -1310,10 +994,6 @@ synack:
 		assert(data_acked <= bufused);
 #endif
 
-		if(data_acked) {
-			buffer_discard(&c->sndbuf, data_acked);
-		}
-
 		// Also advance snd.nxt if possible
 		if(seqdiff(c->snd.nxt, hdr.ack) < 0) {
 			c->snd.nxt = hdr.ack;
@@ -1337,8 +1017,8 @@ synack:
 			c->snd.cwnd += max(1, (utcp->mss * utcp->mss) / c->snd.cwnd); // eq. 3
 		}
 
-		if(c->snd.cwnd > c->sndbuf.maxsize) {
-			c->snd.cwnd = c->sndbuf.maxsize;
+		if(c->snd.cwnd > c->utcp->mtu) {
+			c->snd.cwnd = c->utcp->mtu;
 		}
 
 		debug_cwnd(c);
@@ -1538,7 +1218,7 @@ skip_ack:
 	//   -> sendatleastone = false
 
 	if(hdr.ctl & SYN || hdr.ctl & FIN) {
-		ack(c, has_data);
+		ack(c, NULL, 0);
 	}
 
 	return 0;
@@ -1630,7 +1310,7 @@ int utcp_shutdown(struct utcp_connection *c, int dir) {
 
 	c->snd.last++;
 
-	ack(c, false);
+	ack(c, NULL, 0);
 
 	if(!timespec_isset(&c->rtrx_timeout)) {
 		start_retransmit_timer(c);
@@ -1651,9 +1331,6 @@ static bool reset_connection(struct utcp_connection *c) {
 		return false;
 	}
 
-	buffer_clear(&c->sndbuf);
-	buffer_clear(&c->rcvbuf);
-
 	switch(c->state) {
 	case CLOSED:
 		return true;
@@ -1693,9 +1370,6 @@ static bool reset_connection(struct utcp_connection *c) {
 }
 
 static void set_reapable(struct utcp_connection *c) {
-	set_buffer_storage(&c->sndbuf, NULL, min(c->sndbuf.maxsize, DEFAULT_MAXSNDBUFSIZE));
-	set_buffer_storage(&c->rcvbuf, NULL, min(c->rcvbuf.maxsize, DEFAULT_MAXRCVBUFSIZE));
-
 	c->recv = NULL;
 	c->reapable = true;
 }
@@ -1775,8 +1449,6 @@ struct timespec utcp_timeout(struct utcp *utcp) {
 		if(timespec_isset(&c->conn_timeout) && timespec_lt(&c->conn_timeout, &now)) {
 			errno = ETIMEDOUT;
 			c->state = CLOSED;
-			buffer_clear(&c->sndbuf);
-			buffer_clear(&c->rcvbuf);
 
 			if(c->recv) {
 				c->recv(c, NULL, 0);
@@ -1862,16 +1534,11 @@ void utcp_exit(struct utcp *utcp) {
 		struct utcp_connection *c = utcp->connections[i];
 
 		if(!c->reapable) {
-			buffer_clear(&c->sndbuf);
-			buffer_clear(&c->rcvbuf);
-
 			if(c->recv) {
 				c->recv(c, NULL, 0);
 			}
 		}
 
-		buffer_exit(&c->rcvbuf);
-		buffer_exit(&c->sndbuf);
 		free(c);
 	}
 
@@ -1957,63 +1624,6 @@ void utcp_set_user_timeout(struct utcp *u, int timeout) {
 	}
 }
 
-size_t utcp_get_sndbuf(struct utcp_connection *c) {
-	return c ? c->sndbuf.maxsize : 0;
-}
-
-size_t utcp_get_sndbuf_free(struct utcp_connection *c) {
-	if(!c) {
-		return 0;
-	}
-
-	switch(c->state) {
-	case SYN_SENT:
-	case SYN_RECEIVED:
-	case ESTABLISHED:
-	case CLOSE_WAIT:
-		return buffer_free(&c->sndbuf);
-
-	default:
-		return 0;
-	}
-}
-
-void utcp_set_sndbuf(struct utcp_connection *c, void *data, size_t size) {
-	if(!c) {
-		return;
-	}
-
-	set_buffer_storage(&c->sndbuf, data, size);
-}
-
-size_t utcp_get_rcvbuf(struct utcp_connection *c) {
-	return c ? c->rcvbuf.maxsize : 0;
-}
-
-size_t utcp_get_rcvbuf_free(struct utcp_connection *c) {
-	if(c && (c->state == ESTABLISHED || c->state == CLOSE_WAIT)) {
-		return buffer_free(&c->rcvbuf);
-	} else {
-		return 0;
-	}
-}
-
-void utcp_set_rcvbuf(struct utcp_connection *c, void *data, size_t size) {
-	if(!c) {
-		return;
-	}
-
-	set_buffer_storage(&c->rcvbuf, data, size);
-}
-
-size_t utcp_get_sendq(struct utcp_connection *c) {
-	return c->sndbuf.used;
-}
-
-size_t utcp_get_recvq(struct utcp_connection *c) {
-	return c->rcvbuf.used;
-}
-
 bool utcp_get_nodelay(struct utcp_connection *c) {
 	return c ? c->nodelay : false;
 }
@@ -2034,10 +1644,6 @@ void utcp_set_keepalive(struct utcp_connection *c, bool keepalive) {
 	}
 }
 
-size_t utcp_get_outq(struct utcp_connection *c) {
-	return c ? seqdiff(c->snd.nxt, c->snd.una) : 0;
-}
-
 void utcp_set_recv_cb(struct utcp_connection *c, utcp_recv_t recv) {
 	if(c) {
 		c->recv = recv;